Friction shock-absorbing mechanism



J F. QCONNOR FRICTION SHOCK ABSORBING MECHANISM May 1, 1928.

Original Filed July 23, 1923 Jbbn zaffff cg Z l 2 Sheets-Sheet 1 May 1,1928. 1,667,798 J. F. OCONNOR FRICTION SHOCK ABSORBING MECHANISMOriginal Filed July 2-3, 1923 2 Sheets-Sheet 2 Z 4': c a a I i r gPatented May 1, 1928.

UNITED STATES I 1 1,667,798 PATENT OFFICE.

JOHN F. OCONNOR, OF CHICAGO, ILLINOIS, ASSIGNOIL T W. H. MINER, INC., 0]CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

FRICTION SHO OK-AB SORBING MECHANISM.

Original application filed July 23, 1923, Serial February 15, 1926.

This application is a division of my copending application Serial No.653,11 .11, for friction shock absorbing mechanisms, filed July 23,1923, on which Patent No. 1,586,322

was granted May 25, 1926.

One object of the invention is to pro vide a friction shock absorbingmechanism, more particularly adapted for railway draft riggings,including a friction system comprising wedge friction shoes and wedgemeans co-operating therewith and relatively movable friction elements,wherein the actuating forces for moving said elements relatively istransmitted through the friction 1 shoes.

Another object of the invention is to pro vide a friction shockabsorbing mechanism of the type referred to wherein a graduated actionin both compression and release is obtained by producing a preliminaryaction of the wedge and friction shoes prlor to engagement of themovable friction elements by the shoes.

Other objects and advantages of the inlb vention will more fully andclearly appear from the description and claims hereinafter following.

In the drawings, forming a part of this specification, Figure 1 is ahorizontal, longitudinal, sectional view of a port1on of a railway draftrigging showing my improvements in connection therewith. Figure 2 is avertical, transverse, sectional view corresponding substantially to theline 22 of Figure 1.. Figure 3 is a detailed, perspec tive view of oneof the friction shoes. And Figure 41 is a side elevational view of oneof the fixed friction elements employed in connection with my improvedmechanism.

In said drawings, 1010 den'ote channelshaped center or draft sills of arailway car underframe, to the inner surfaces of which are secured frontstop lugs l1-11 and rear stop lugs 12-42. The inner end portion of thedrawbar is designated by 13, the same being operatively connected with ahooded yoke 14 within which is disposed the shock absorbing mechanismproper, a front follower 15 and a rear follower 16. The yoke and theparts ther-ewithin are supported in operative position by a detachablesaddl plate 17 fixed to the draft sills.

The improved shock absorbing mechanism proper, as shown, comprises,broadly, a coin- No. 653,114. Divided and this application filed SerialNO. 88,192.

bined friction shell and springcage casting A; a centralwedge l3; apairof wedge friction shoes CC; two sets of movable friction plates DD; twosets of relatively stationary friction plates E'-E; aspring resistanceelement F; a spring follower G; and a retainer bolt H. i i

The casting A which is of generally rectangular form is provided atitsfront end with a friction shell proper and rearwardly thereof withthe spring cage section. The casing has horizontally disposed, spaced,to and bottom walls 18-18, vertically disposed spaced, side walls 19-19,and a transverse rear end wall 20. The end wall 20 bears directly on therearfollower 16 which in turn co-operates with the stop lugs 12. Theside walls 19 are provided with longitudinally disposed flat interiorfriction surfaces 21- 21, the surfaces 21 converging slightly reaiwardlyof the mechanism. At the rear end of each of the-friction surfa'ces 21,the side walls 19 of the casing are provided with pairs of inwardlyprojecting lugs 22-22, each pair of lugs being spaced apart verticallyas most clearly shown in Fig ure 2.

The central wedge B is in the'form of a hollow block having a flat frontend face 23 hearing directly on the inner surface of the front follower15. At the inner end, the wedge block B is provided with a pair ofrearwardlyconverging flat wedge faces 24 adapted to cooperaterespectively wit-h 'the two friction shoes C. i

The friction shoes C are of like construction and are arranged onopposite sides of the wedge B. Each friction shoe G is in the form of anelongated block having a lateral enlargement on the inner side thereofprovided with a front wedge face 124: correspondingly inclined to andadapted to co-operate with the wedge face 2 1 at the same side of thewedge B. At the front end, each shoe 0 has a lateral flange 25 adaptedto co-operate with the movable plates as hereinafter more fullydescribed. At the rear end, each shoe 0 has an extension 26 providedwith a lateral, outwardly extending lug 27 adapted to co-operate withthe rear ends of the movable friction plates D.

The friction plates D and E are disposed within the friction shell andcomprise two oppositely arranged groups. As herein shown, the groups ofplates each comprise three plates D and three plates E, the plates D andE being alternated with one of the plates D of each group disposedoutermost and co-operating with the corresponding friction surface 21 ofthe casing A. One of the plates E of each group is disposed innermostand co-operates with the corresponding friction shoe, each of the shoesbeing provided with an outer flat friction surface bearing on theinnermost plates E of the two groups. The plates D are all of likeconstrnction and as most clearly shown in Figure 1 are of substantiallyrectangular outline and of a length less than the distance between thellange 24 and the lug 9.1 of the corresponding friction shoes. Theplates E are also of like design and as best shown in Figure 4, eachplate E is of substai'ltially rectangular outline. The plates E arelonger than the plates D and each of the same is longitudinally slottedat the center as indicated at 28 to accommodate the corresponding lug 27of the friction wedge shoe at the same side of the mechanism. The slots28 are of such a length as'to permit the proper amount of movement ofthe friction shoes during compression of the mechanism. Each plate E isnotched at the top and bottom edges thereof as indi ated at 2.29. Thenotches 29 are disposed closely adjacent the rear end of the plate andare adapted to receive the lugs 22 at the same side of the mechanism.The plates E of each group are thus anchored to the casing A againstlongitudinal movement, but are adapted to have certain amount of lateralmovement.

The spring resistance elenu-nt i comprises a relatively heavy outer coiland a lighter inner coil, the outer coil having its opposite endsabutting) respective the rear wall 20 of the casing A and the springfollower G. The rear end of the outer coil of the spring is centered byan inwardly projecting hollow boss 30 on the rear wall 20 of the casing.The inner coil of the spring resistance has its opposite ends abuttingrespectively the spring follower G and the boss 30. As shown, the springfollower is interposed between the main spring resistance F and bears onthe inner ends of the enlargements of the friction shoes C.

The shock absorl'iing mechanism held in assembled relation and underinitial compression by the retainer bolt H passing through the innercoil of the springresistance and aligned openings of the wedge block Bspring follower plate G and the boss 30, having its opposite endsanchored in the wedge B and the boss 30 respectively.

The normal position of the parts is that shown in Figure 1, wherein themovable friction plates D have their front ends spaced slightly from theflanges 25 of the shoes C and their rear ends bearing on the lugs 27 ofthe shoes. The llanges of the shoes C are spaced a suilicient distance'flOl'll the rear surface of the front follower 15 so that when themechanism is fully con'iprcsscd, there will still be clearance betweenthe follower and the flanges of the shoes.

The operation of the improved shock absorbing mechanism is as follows,assuming an inward or balling movement oi." the drawbar: Upon inwardmovement of the drawbar, the follower 15 will be forced rearwardly,thereby moving the wedge l inwardly of the casing A. and setting up awedging action between the wedge and the friction shoes 0. Due to thespreading action of the wedge, the friction shoes will he forced againstthe two groups of friction plates, pressing the same into intimatecontact. During the initial compression of the mechanism, there will beno movement of the movable ,l'riction plates with reference to theplates E, but the friction shoes will be carried inwardly of thestationary plates, friction being created between the enacting surfacesof the shoes and the innermost plates of the two groups. This actionwill continue until the flanges 25 of the friction shoes engage thefront ends of the movable plates D, whereupon the plates I) will beforced to more in- 'ardly in unison with the shoes aml relativcly to thestatirnulr plates i During the action justdcscribed, the resistance willbe greatly augmented due to the friction created between theintcrcalatcd plates. During the initial action hcreinbel'ore described,the shoes are moved inwardly rel atively to the plates D, the lugs 27 ofthe shoes will move away from the inner ends of the plates D, therebyproviding a certain amount of clearance which is maintained during theentire compression stroke and is available when the gear released topermit the shoes to move outwardly a limited distance with reference tothe plates D before the plates are actually engaged by the lugs 27 torestore them to normal position. The compression of the mechanismcontinues either until the actuating force is reduced or until the frontfollower engages the front end of the casing A. Upon engagement of thecasing A by the follower 15, the actuating force will be transmitteddirectly through the casing to the rear follower and the rear stop lugs,the casing acting as a solid column to transmit the load, thus relievingthe spring resistance from excessive compression.

lVhen the actuating force is reduced, the expansive action of the mainspring resistance F will force the friction shoes and wedge B outwardly.lnttHl'l'lllt'll as clearance provided between the lugs 27 and the innorends of the movable plates D during compression of the mechanism, thewedge Hill block and the friction shoes will be forced outwardlyindependently of the plates D during the initial releasing action,thereby greatly facilitating this operation. As the shoes are movedoutwardly, the lugs QZwill pick up the plates D and return them to theposition shown in Figure 1. Outward move ment of the wedge D is limitedby the retainer bolt and the shoes have their outward movement limitedby their contact with the wedge members.

WVhile I have herein shown and described what I now consider thepreferred manner of carrying out my invention, the same is merelyillustrative, and I contemplate all changes and modifications that comewithin the scope of the claims appended hereto.

I claim:

1. In a friction shock absorbing mecha nism, the combination with acolumn load sustaining member; of a plurality of friction elements,certain of said elements being fixed against longitudinal movement withreference to said member, and the remaining elements being movablelongitudinally of said member; a wedge friction system cooperating withsaid element-s, said system including a wedge member and friction shoes;means on said shoes co-operating with the front and rear endsrespectively of said movable element for effecting longitudinal movementthereof inwardly and outwardly with reference to said member; and aspring resistance opposing movement of said shoes.

2. In a friction shock absorbing mechanism, the combination with afriction memher; of a plurality of friction elements cooperating withsaid member, certain of said elements being fixed against longitudinalnally of said member, said means including friction shoes; means on saidshoes normally spaced from the outer ends of said movable elements andengageable with said last named elements for actuating the same after apredetermined compression of the mechanism; and spring means co-operatmgwith said spreading means.

3. In a friction shock absorbing mechanism, the combination with afriction shell; of a plurality of friction plates within the shell,certain of said plates being fixed against longitudinal movement and theremaining plates being movable relatively to said first named plates;wedge pressure'creating means co-operating with said plates, said meansincluding a main wedge and a pair of friction shoes, said shoes havingmeans at the front and rear ends thereof cooperating with the oppositeends of said movable plates for effecting movement of the same, saidmeans being spaced apart a distance greater than the length of saidmovable plates; and spring resistance means opposing movement of saidshoes.

In witness that I claim the foregoing I have hereunto subscribed my namethis 10th day of February 1926.

' JOHN F. OCONNOR.

